Alma 34:9

for it is expedient that an atonement should be made; for according to the great plan of the Eternal God, there must be an atonement made, or else all mankind must unavoidably perish; yea, all are hardened; yea, all are fallen, and are lost, and must perish, except it be through the atonement which it is expedient should be made;

This payment must be made. God’s great plan says there must be a payment made. If not, all people must die. All people have hard hearts. All people have fallen and are lost. They must die unless this payment is made.

An atonement has to be made. According to the eternal plan of God, there must be an atonement, or all humanity will inevitably perish. We’re all hardened. We’re all fallen, lost, and headed for destruction—unless the atonement is made.